A clutch device that intermittently transmits a rotational force to a rotating member is known. The clutch device includes a gear having a toothless portion, a cam rotatable integrally with the gear and including an engagement portion, an electromagnetic solenoid having an energized state and a de-energized state, a lever, and a spring. The lever includes a hook engageable with the engagement portion. The lever is attracted by the electromagnetic solenoid in the energized state. The spring urges the lever in a direction in which the hook and the engagement portion engage with each other.
The clutch device has an output stop state and an output state. In the output stop state, the electromagnetic solenoid is in the de-energized state, the lever is urged by the spring, and the hook and the engagement portion engage with each other, and rotation of the gear is restricted. In the output state, the lever is attracted by the electromagnetic solenoid in the energized state against the urging force of the spring, the engagement between the hook and the engagement portion is released, and the gear is allowed to rotate. The cam includes a first cam surface downstream from the engagement portion in a direction opposite to a direction of rotation of the cam, and a second cam surface downstream from the first cam surface in the direction opposite to the direction of rotation of the cam. The second cam surface is located in a position where a distance from a center of the cam to the second cam surface is greater than a distance from the center of the cam to the first cam surface.
The clutch device operates as follows.
When the clutch device is in the output stop state where the hook and the engagement portion engage with each other, and the electromagnetic solenoid is switched to the energized state, the lever is attracted by the electromagnetic solenoid and comes into contact with an abutment portion of the electromagnetic solenoid, the hook moves away from the engagement portion, the gear is allowed to rotate, and thus the clutch device enters the output state. When the clutch device is in the output state, the cam rotates together with the gear, and the first cam surface of the cam faces the hook of the lever. The first cam surface is spaced from the hook.
In this state, when the gear further rotates, the second cam surface of the cam faces the hook. The second cam surface contacts the hook, and presses the hook toward the electromagnetic solenoid. The lever, with the hook pressed toward the electromagnetic solenoid by the second cam surface, is configured to pivot, like a seesaw, about the abutment portion of the electromagnetic solenoid against the urging force of the spring.
In this state, the cam rotates with the hook being pressed against the second cam surface by a pressing force of the second cam and the urging force of the spring.
With the hook being pressed against the second cam surface, the clutch device switches the electromagnetic solenoid from the energized state to the de-energized state. Then, the cam rotates with the gear, the hook engages with the engagement portion, and the clutch device enters the output stop state.
The clutch device switches the magnetic solenoid from the energized state to the de-energized state with the hook being pressed against the second cam surface. Thereby, the clutch device prevents an impact noise from occurring when the hook contacts the cam.